1. Field of the Invention
This invention relates to a process for preparing a porous metal plate, and more particularly a process for making a porous metal plate of short metal fiber and metal particulate.
2. Description of the Prior Art
Recently, a porous metal material has been extensively used for a variety of applications. For example, a porous nickel material and a porous aluminum material are used for a fuel cell and a sound absorption material, respectively. Also, a porous stainless steel material is applied to a filter and used for catalyst and the like.
Although various kinds of porous metal materials as described above have been improved for satisfying such applications, it is still highly desired to develop techniques of preparing a porous metal material having porosity depending upon the applications.
A porous metal material which has been prepared according to a conventional process generally has porosity substantially varied depending upon the manufacturing process and/or metal to be used therefor.
More particularly, in general, sintered powder has porosity of 10-60% irrespective of metal to be used, whereas a metal fiber felt and sponge metal have that of 50-80% and 80-95%, respectively. Such porosity is varied depending upon the manufacturing process of porous metal. Also, some metal fails to provide a porous metal body other than a sintered body. Thus, it will be noted that the porosity of a porous metal material prepared is restricted within a limited range.
Further, conventional sintered metal has disadvantages that its bending strength is decreased to a degree sufficient to deteriorate workability and it is inconvenient to be handled, resulting in being restricted to use only at a limited place.
Furthermore, a porous metal material such as sintered powder, metal fiber felt, sponge metal or the like which is prepared according to a conventional process is substantially hard to be formed into a sheet-like shape having a large area. Also, it is not made to have a thickness above 10 mm and an area above 50 cm.times.50 cm. Thus, it will be noted that the shape and dimensions of porous metal each are limited to a narrow range.